Ignition control system



E. CLAYTOR 2,257,838

IGNITION CONTROL SYSTEM Oct. 7, 1941.

Filed March 25, 1940 INVENTOR z 5%! I v AITTORNEW Patented Oct. 7, 1941 Edward M. Claytor, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich, a

corporation of Delaware Application March 25, 1940, Serial No. 325,705

6 Claims. (or 74-41:)

This invention relates to electrical systems for controlling an automobile overdrive and more particularly to electrically operated means for momentarily rendering the engine inoperative in order to facilitate the automatic function of the overdrive mechanism when shifting from one chain of gears to another.

In my copending application Serial No. 290,356 filed August 16, 1939, I disclose a time-lag or measured-time relay which is preconditioned for operation when going into overdrive so that, automatically in response to a driver operation of the control system for the purpose of coming out of overdrive, the measured-time relay functions to render the engine ignition inoperative for a predetermined time interval suflicient to facilitate the automatic functioning of the overdrive mechanism in coming out of overdrive. The system of my application Ser. No. 290,356 operates to go into overdrive above a predetermined vehicle speed when the regular transmission gears are in high speed (1 to 1 gear ratio) position.

The object of the present invention is to proholding the gear 8 stationary comprises locking pawl 22 received by one of a series of notches |2 in a ring it attached to sun gear 6. The pawl 22 is normally'maintained' out. of engagement with the ring II by a pawl rod 22" which is controlled in amanner to be described.- Movement of the pawl 22 into engagement with-the ring II is obstructed, except under certain conditions, by a blocker plate l2 which is frietionally dragged by ring H. The blocker plate i! is provided with stop lugs l4 and II which project beyond stop surfaces It and II which may be engaged under Bosses l9 and 2. project into blocker plate I! so as to be 'eng "ged by lugs ll and I5, respectively. When -thering ll rotates certain conditions by the pawl 22. The surfaces It and H are interrupted by a notch l8 of suill-' cient width to permit movement of the pawl 22 between the surfaces ii and II when the notch II is brought into alignment with the-pawl 22. The pawl 22 is guided between bosses I! and 20 of the frame 2| ofthe overdrive mechanism. tze plane of the I clockwise, the blocker-plate B will be frictionally vide an auxiliary control system by which momentary disabling of the engine ignition can be eflected at a speed in a speed rangelower than the speed range within which the automatic change from one-to-one gear ratio to an overdrive gearratio is efiected by the type of mechanism disclosed in my application Ser. No.

290,356. Such auxiliary control system would be useful, for example, in' facilitating the functioning of an automatic mechanism which controls the changebetwee'nthe second or intermediate speed gear train and the thirdor normal high speed gear train, for example, according to .vehicle speed.

Further objects and advantagesof the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

Inthe drawing:

Fig. 1 is a wiring diagram disclosing an embodiment of my invention.

A shaft 5. driven by the engine through one of the gear trains of the regular change speed gearing of the automobile, transmits power either through a 1 to 1 ratio drive to the propeller shaft or through an overdrive which includes concentric rings and sun gears and intermediate planet gears, the'sun'gear being held stationary when the overdrive operates. drive is known to those skilled in this art. only the sun gear 6 is shown. The mechanism fordragged clockwise until its lug ll strikes the boss l9, and further movement of the blocker plate l3 in the clockwise directi will cease when the ring ll rotates counterc pckwise, the blocker plate 13 will be frictionally dragged counterclockwise until its lug l5 engages the boss 20 whereupon counterclockwise movement of the plate It will cease. 1 1

The sun gear locking wi 22 is attached to a pawl rod 22 forming part of asolenoid unit 30.

Rod 23 extends through stationary core 24 and through a solenoid armature 25. Rod 23 has-a between the shoulder 2i and a nut 29 threadedly attached to the armature 25. Nut 29 has a flange 3| engaged by coil spring 32 located in a state of compression between flange 3| and a stationrelatively small number of turns of relatively As this form of overcoarse wire. Terminal 43 is connected with solenoid holding coil II which comprises a relatively large number of turns of fine wire. Holding coil 4! is grounded at 4'! a. The rod 22 extends through the nut 3I and the stationary stop plate 34 to engage leaf spring contact 48 connected with a terminal 48a. Contact 48 engages a nonconducting block 44 attached to a resilient contact arm 45 carrying a contact 46 normally out of engagement with contact 41 which is grounded at 41a. Arm 45 is connected with a terminal 48. A generator 50 is connected through a reverse circuit relay 5|, an ammeter 52 and-a wire 53 with a storage battery 54 grounded at 55. A wire 56 connects wire 53 with terminal 6I of a relay 60. Relay 60 comprises a core 62 surrounded by a magnet winding 63 connected with terminal BI and with a terminal 64. Terminal 6| is connected with an armature 65 normally resiliently urged away from the core 62. Armature 65 carries a contact 66 for engaging a contact 61. Armature 65 insulatingly supports a contact 13 normally engaging a contact 14 connected with a terminal 15. i

Numeral 80 designates a measured time relay having a core 8I surrounded by a magnet coil 82 connected with terminals 84 and 90. Core 8I cooperates with an armature 65 normally biased away from the core and carrying a contact 86 engageable with a contact 81 connected by a wire 88 with contact 13 of relay 60. A short circuited coil 83 surrounds core ill for the purpose to be described later.

Wire 9I connects contact 61 of relay 60 with terminal 90. Indicator lamp 92 and wire 83 are connected between terminals 90 and 48a. Wire 94 connects terminals 90 and 42. Wire 95 connects terminals 89 and 48. Wire 96 connects terminals 84 and 43.

Numeral I designates an ignition coil having a primary IM and a secondary I02. Primary IOI is connected with wire 53 through an ignition 'switch- I03. Primary I0! is connected with a terminal I04 and with an ignition timer I grounded at I06. Terminal I04 is connectedby a wire I01 to the terminal of relay 60.

Terminal 64 of relay 60 is connected with a gear switch I having stationary contacts I2I and I22 adapted to be bridged by movable contact I23 held outof engagement with stationary contacts by a spring I24. The gear switch I20 is closed by mechanism for controlling the connection of certain trains of gears between the engine shaft and the propeller shaft of the automobile. For example, switch I20 may be closed by mechanism which is actuated when the manually operated gear shaft lever is in high speed position.

Switch I20 is connected with kick switch I comprising stationary contacts I26 and I21 normally engaged by contact I28 held normally in contact closing position by a spring I29. The switch I25 is opened by a suitable pedal cooperating with a switch actuating rod I25a. This pedal may be the engine throttle or accelerator pedal which causes the switch I25 to open by movement of accelerator pedal beyond wide open throttle position.

Switch I25 is connected with a ground through a switch responsive to vehicle speed such as an air switch I having a grounded vane I 3| pivoted at I32 maintained normally out of engage- I ment with contact I 83 by a spring I34. The vane I3I is moved into engagement with contact I33 by the action of an air current provided by the engine cooling fan I35 which causes a current of air to impinge upon the vane I3I as indicated by the arrow I36.

The operation of the overdrive controlsystem ipcluded inFlg. 1 is as follows: While the engine is running the ignition switch I03 will be closed. When the vehicle transmission is set to drive through the normal high speed (1 to 1 ratio) gear train, the switch I20 will be closed. When the vehicle speed attains a certain value such as 25 M. P. H. for-example, the air switch I30 will be closed. As stated before, switch I25 is normally closed. .All threeswitches I20, I25 and I30 being closed, the winding 63 of relay 60 will receive current from the battery 54 thereby causing armature 65 to be attracted and contacts 66 and 61 to be engaged. Movement of contact 65 toward core 62 causes contact 13 to be separated from contact 14 thereby interrupting any ground connection which could be made with terminal I04 between timer I05 and coil I00.

When contact 66 engages contact 61 the solenoid magnets 40 and H will be connected with the batterythrough the following circuit: Battery 54, wire 56, terminal 6|, armature 65, contact 66, contact 61, wire 9|, terminal 90, wire 84, terminal 42, winding 40, contact 31, contact I 36, arm 35, ground 38 and battery ground 55. From terminal there is a branch circuit through windings 8'I and4I to ground 4Ia. Both windings 40 and 4I cooperate to attract solenoid armature 25 toward core 24. As armature 25 moves downwardly, it carries with it the nut 28 which urges the upper end of the spring 28 downwardly thereby tending to move the rod 23 downwardly.

When the solenoid is not excited, the spring 32, acting through the. pawl rod 23, keeps pawl 22 out of engagement with the blocker plate I3. When the engine drives the transmission, the ring II moves counterclockwise as viewed in Fig. 1 and the plate I3 is frictionally dragged counterclockwise so that its lug I5 engages boss 20 thereby causing surface I1 to be in the path of movement of the pawl 22. When the engine speed is increased to the speed where the governor switch I30 closes, the hand controlled change speed gearing being in high gear, the solenoid will be energized in the manner described. The pawl 22 is then urged downwardly by spring 28 and presses against surface I1. Engagement of the pawl 22 with the notched locking ring II is prevented until the speed of ring II is reduced to zero and'the rotation of ring II reverses.

The reversal of ring II is effectedby a reduction of engine speed (measured in miles per hour of vehicle speed) below vehicle speed by a predetermined amount dependent upon the gear ratio of overdrive to normal drive. For example,

if the overdrive increases the speed ratio between vehicle-drive wheels and the engine by 30%, the engine speed must be reduced below vehicle speed by the amount of 30% of vehicle speed. Assuming the vehicle is being propelled through normal drive at 40 M. P. H. and it is desired to go into overdrive, the driver releases the accelerator pedal to permit engine speed to decrease. The vehicle free wheels" (through an overrunning clutch, not shown, connected between the shaft 5. and the ring gear of the overdrive) at a speed starting at 40 M. P. H. and diminishing slightly due. to resistance of wind and friction to about 35 M. P. H. Meanwhile the engine speed has diminished to 24 M. P. H., which speed is slightly more than 30% less than 35 M. P. H., the concurrent vehicle speed. As the engine speed decreases to 24 M. P. H., the speed of ring II is reducedto zeroand then the ring II starts to reverse in direction of rotation. or to move clockwise as viewed in Fig. 1. As ring I] begins to the contacts of relay 68, 'the contact 86 of relay move slowly clockwise, it drags frictionally the blocker plate l3 clockwise thereby causing its lug l5 to move away from the boss 28 and its notch |.8 to become aligned with pawl 22 thereby permitting spring 28 to press pawl 22 against a tooth of ring As ring continues to rotate, it

- 88 returns to normal open position and operabrings a notch |2 into alignment with ,pawl 22 v thereby permitting spring 28 to press pawl 22 into locking engagement with the ring thereby locking sun gear 6. While the sun gear 6 is locked, transmisison of power from the shaft I to the propeller shaft takes place through the overdrive comprising planet gears (not shown), moved orbitally by shaft l5 around the sun gear 6, and a ring gear (not shown) driven'by the planet gears at a speed greater than the speed of shaft 5.

During movement of the solenoid armature 25 toward the core 24 in order to preload the spring 28 so that it may'push the pawl 22 into a notch |2 of the sun gear locking ring II when the blocker i3 is retracted, the -flange 3| of nut 29 engages the resilient contact arm 35 thereby separating contact 38 from contact 31 and breaking thecircuit through the main attracting coil 48 of the solenoid. The armature 25, being then in relatively close proximity with the core 24, is llie4lcll in the attracted position by the holding C01 When contacts 66 and.61 of relay 68 are closed, winding 82 of relay 88 is connected with the battery 54. Armature 85 is attracted toward core 8| to' cause the contact 86 to engage contact 81.

Armature 85 seats on core 8| for a purpose to i be described.

During downward movement of pawl rod 23, the downwardly biased resilient arm 45 causes contact 46 to move into engagement with contact 41. The circuit for grounding the ignition apparatus and thereby rendering it inoperative comprises wire I81 connecting terminals I84 and 15, contacts 14 and 13 of relay 68, wire 88, contacts 81 and 86 of relay 88,'armature 85, terminal 89, wire 85, terminal 49, arm 45, and

contacts 46 and 41. While the pawl 22 engages the sun gear locking ring II to render the overflow of current through the magnet winding 82 of relay 88 and through the solenoid holding coil 4|, thereby permitting relay 88 and solenoid armature to return to normal positions.

The ignition is momentarily rendered inoperative because relay 88 delays separation of contacts 86-81 for a brief interval, thus rendering the engine inoperative and thereby producing a condition favorable to the retraction of pawl 22 by spring 32. When the holding coil 4| is deenergized, spring 32, by operating through the nut 21, and the nut 21, by operating on the shoulder 26 tends to cause the pawl rod 23 and the pawl- 22 to be restored to normal position. During upward movement of rod 21, the resilient contact arm 35 is relieved from engagement with the flange 3| of nut 29, thereby permitting the contact 36 to reengage the contact 31.

A predetermined time after the separation of tion of the ignition is restored. This predetermined time is measured or determined by the relay 88. The lag or time delay between the opening of contacts 66 and 61 of relay 68 and the opening of contacts 86 and 81 of relay 88 is effected by causing the armature. 85 to seat or seal against the core 8| of relay 88 when its contacts are closed, thereby making it necessary for the magnetic the core 8| to diminish substantially ;to-z'ero. before the am:

ture 85 is released. The decay of flux in the core 8| is retarded by the short circuited coil 83 and also by reason of the fact-that the inductive kick (self-induced voltage). from holding coil 4|, which occurs at the instant of separation of contacts 66-61 of relay 68, acts upon coil 82 in such direction as to produce a flux assisting the original flux in core 8|. During this measured time .interval between the opening of contacts 86-81 of relay 88, the ignition terminal I84 is-grounded due to the fact that all of the pairs of contacts 13-14, 86-81 and 46-41are then closed. The grounding of the ignition coil |88 eliminates the igniting of several charges of fuel thereby causing the engine to cease to drive the vehicle and thereby relieving the torque reaction between the sun gear locking ring II and the pawl 22 in order to facilitate retraction of the pawl by the spring 32.

The pawl 22 having been relieved of a pres- .sure placing a frictional drag on" the pawl, the

pawl 22 and its rod 23' move upwardly due to the action of the spring 32. By the time that the pawl 22 has been fully retracted from the sun gear locking ring II, the rod 23 will have actuated the insulating button 44 'of the contact arm .45 thereby causing contact 46 to move out of engagement with contact 41, thereby interrupting the grounding circuit of theignition terminal I84. Therefore, as soon as the looking pawl 22 has been fully retracted from the sun gear locking ring II, the ignition grounding circuit will be broken. Under normal conditions the contacts 46-41 will open sooner than the contacts of relay 88. However, the opening of the contacts 46-41 is contingent upon the retraction of the sun gear locking pawl 22 by the spring '32. In case the pawl 22is not retracted for any reason, such as failure of the return spring 32, the relay 88 finally operates to interrupt the ignition grounding circuit, thereby causing the ignition to be reestablished regardless of whether the overdrive has been rendered inoperative. Therefore the circuit operates whenever the driver desires to come out of overdrive in a manner suchas to disable the ignition in order to facilitate coming out of overdrive under normal conditions. However, in case of failure of the vehicle transmission to come out of overdrive, the ignition is reestablished after a time which should be suificient for the vehicle transmission to come out of overdrive under normal circumstances. In other words, under normal conditions, the contacts 46-41 open ahead of the contacts of relay 88 to interrupt the ignition grounding circuit. But, should the contacts 46-41 fail to'open to reestablish the ignition circuit, the relay 88 will eventually open after a measured time interval in order that less of failure of the vehicle transmission to come out of overdrive.

ing of contacts 6661 of relay 60 to close the circuit of the solenoid winding 404I. Lamp 32 ceases to burn when rod 23 descends to move pawl 22 into locking position, thereby indicating, by ceasing to burn, that the transmission is in overdrive.

There is a time interval of appreciable duration between the rendering of the ignition inoperative and the restoration of the ignition to operative condition; consequently, there have been brought about two separate instances where conditions are favorable to the retraction of the pawl from sun gear locking position by the pawl returning spring. I shall explain first the instance where the ignition is rendered inoperative. It will be understood there is a certain amount of lost motion or side play between the pawl 22 and the sides of a notch I2 of the lockingring II. While the engine ignition is operative and the engine drives the vehicle, the torque transmitted by the engine to the vehicle drive wheels is what -may be termed positive torque. When the engine ignition is rendered inoperative, the vehicle tends to drive, the engine and the transmission of torque is reversed. This reversed torque may be termed negative torque. When positive torque is present the pawl 22 will press against one side of a notch I2 and, when negative torque is present, the pawl 22 will press against the other side of the notch I2. It is obvious that, if the ignition is rendered inoperative causing the engine to cease to fire, the torque will change from positive to negative and the pawl 22 will move from a position where it presses against one side of the notch I2 to a position where it presses against the other side of the notch. During the period of time of relative sidewise movement between the notch I2and the pawl 22 in which the pawl 22 relatively moves from one side of the notch I2 to the other, there is a condition where there is no binding force between the ring II and pawl 22 to resist withdrawal of the pawl 22 by the pawl return spring a second speed to a third speed.

32. This change from positive torque to negative torgue produces a condition which is favorable to the retraction of the pawl 22 from the ring II.

Obviously the duration of this condition is relatively short, since it continues only long enough for the pawl to leave one side of the notch, traverse the lost motion space between i the sides of the notch and then engage the opposite sides of the notch. 'Under some unusual circumstances, this period of short duration might not be suflicient for the pawl 22 to be completely withdrawn from the sun gear locking ring II. However, another instance of favorable conditions for retraction of the pawl 22 by the spring 32 is afforded.

At the end of the measured time interval provided by relay 80 during which the ignition may be inoperative, there is another condition of no binding between the pawl 22 and ring ,II at the instant when the ignition apparatus is rendered operative, because there is another reversal of torque from negative torque to positive torque. Therefore, the system provides two instances which are favorable to the retraction of the pawl 22 of the sun gear locking ring II. Therefore there are two opportunities for the pawl 22 to be retracted.

The apparatus thus far described takes care of the change from normal third or high speed (1 to 1) gearratio to an overdrive gear ratio and back again. I wish also to provide for the ignition switch I03.

momentary interruption of engine torque in order to facilitate the change in gear ratio which might be brought about automatically while the vehicle is operating at speeds lower than the speed at which the overdrive could be rendered operative. For example, the power transmission from the engine might include means responsive to vehicle speed for automatically shifting from In suchcase, it is necessary that such automatic change speed mechanism be relieved of engine torque during the transition between gear trains. Therefore, I provide an auxiliary electrical system including a measured-time relay which, in response to the closing of the ignition switch, is so preconditioned that, when it is desired to shift from a gear train of one ratio to a train of another ratio, the engine ignition is rendered inoperative momentarily so that this shifting will be facilitated.

This auxiliary electrical system includes a control relay I40 having a core I surounded by a magnet coil I42 connected with terminals I48 and I5l, and an armature I43 connected'with terminal I48 and carrying insulatingly a contact I44 normally engaging a contact 145 connected with a terminal I46 connected by wire I41 with terminal 15 of relay 60. Terminal I48 is connected by wire I49 with contact I03a of Armature I43 carries contact I52 normally disengaged from contact I53 connected with wire I54. Contact I44 is connected with wire I55.

Terminal I5I of relay I40 is connected with foot operated switch I having stationary contacts I6I and I62 normally bridged by movable contact I63 urged by spring I64 against contacts I6I and I62, and moved" away from said contacts by a plunger I65 which might be pushed down, for example, by movement of the accelerator pedal to an extreme position nearest the toe-board. Contact I62 is grounded at I66.

Relay I40 controlsa measured-time relay I 10 comprising a core I'II, a coil I12, connected between terminals I13 and I14, and an armature I16 connected to terminal I11 and carrying a contact I18 normally disengaged from a contact n9 connected with wire-I55. Wire I54 is connected with terminal I13. Terminal I 14 is grounded. A non-inductive resistance I 15 connected between terminals I13 and I14 operates -from contact I45.

to resist decay of flux of the relay I10 when the circuit between the battery 54 and the magnet coil I12 is broken at contacts I52 and I53 of control relay I40. "I11 around core I also operates to resist flux decay.

Terminal I11 is connected by wire "1a with a vehicle speed responsive air switch I comprising a stationary contact I8I and an air-vane contact I82 normally urged by a spring I04 against contact I8I. Vane I82 is pivoted upon a grounded pivot I03.) The vane I82 is impinged upon by an air current represented by arrow I86 produced by the engine cooling fan I85. Switch I80 opens at a vehicle speed lower than the speed at which air switch I30 closes.

The operation of the auxiliary circuit is as follows: When the ignition switch I03 is closed,

the circuit between the battery 54 and the coil I42 of relay I40 is completed to effect attraction of armature I43 thereby causing contact I52 to engage contact I53 andcontact I44 to separate Thenthe circuit 'between battery 54 and coil I12 of relay I" is completed The short circuited coil to cause armature I16 to move toward and to seal against the core HI and to close contacts I18 and I19.

The circuit which momentarily renders the ignition inoperative is an ignition coilshort cir-.

cuit which includes wire I01, wire I41, terminal I46, contacts I44--I45 of relay- I40, contacts I18--I'I9 of relay I10 and contacts I8I,I82 of air switch I80. Upon the closing of ignition switch I03, contacts Ill-I45 open ahead of the closing of contacts I18-I19. Hence the i nition coil short circuit is never completed until the.

non-operative.

I60 interrupts the.

The opening of switch rendering the ignition withholding means efiective and means responsive to vehicle speed for causing the ignition withholding means to be ineffective.

3. An ignition control system for automotive use comprising a current source, electrical ignition apparatus,'a switch for connecting the ignition apparatus with the battery, a measured-' time relay having a switch normally positioned for the purpose of permitting operation of the ignition but movable to a position for withholding operation of the ignition when its magnet coil is energized, and a control relay having its magnet coil energized in responseto the closing of the ignition switch and having a switch closed jin response to energization of its magnet coil for the purpose of connecting the current source circuit between battery 54 and relay coil I40 I Due to the elements I15 and I1Ia and to the fact that the armature I16 seals against the core "I, the contacts I19-I18 remain closed for an appreciable time to cause the engine ignition to be rendered non-operative for a time sufiicient for the shifting of gear trains.

Above a vehicle speedless than the speed 'at which switch I30 closes, the switch I80 opens to maintain open-circuited the ignition short circuit controlled by the auxiliary system. Hence the auxiliary system is non-operative over the .speed range within which the overdrive control is operative.

with the measured-time relay magnet coil andhaving a secondswitch in series with the measured time relay switch and being normally in position to control a circuit to render the ignition inoperative-but which moves to a position for the purpose of permitting operation of the ig- To secure more uniform operation, the cores or the armatures. of relays 80 and- I10 should bechromium plated so that the armatures do not seal against. the cores with iron-to-iron contact. The reasons ,for this are fully disclosed in my copending application Serial No- 290,356 filed August 16, 1939; v

While the embodiment of'the present inven-' tion as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows: l

1. An ignition control. system for automotive use comprising a current source, electr'ical ignition apparatus, a switch for connecting the ignition apparatus with the battery, means for withholding the operation of the ignition appaconditioning said ignition withholding means for operation, means controlled by the driver for nition when the control relay magnet coil is energized, and means under the control of the driver for rendering the control relay inoperative.

4. An ignition control system for automotive use comprising a current source, electrical ignition apparatus, a switch for connecting the ignition apparatus with the battery, a measuredtime relay having a switch normally positioned for the purpose of permitting operation of the ignition but movable to a position for withholding operation of the ignition when its magnet coil is energized, anda control relay having its magnet coil energized in response to the 'closing of the ignition switch and having a switch closed in response to energization of its magnet coil for the purpose of connecting the current source with the measured-time relay magnet coil and having a second switch in series with the measured time relay switch and being normally in position to control a circuit to render the ignition inoperative but which moves to a position for the purpos of permitting operation of the ignition when the control relay magnet coil is energized,qmeans under-the control of the driver for rendering the control relay inoperative and a vehicle speed responsive switch in series with the measured-time relay switch and with the second switch of the control relay, said vehicle speed switch being normally in a position for Iii) rendering the ignition inoperativ but movable upon attainment of a certain vehicle speed to render the control relay and measured-time relay ineffective to control the ignition.

5, An ignition control system for automotive use comprising a current source, electrical ignition apparatus, a switch for connecting the ignition apparatus with the battery, an automobile overdrive, an overdrive operating solenoid, a measured-time relay having a switch normally in position for permitting operation of the ignitionjapparatus but movable to a position to render the ignition inoperative when the magnet coil ofthe measured time relay is energized, a control relay rendered operative in response to the attainment of a certain vehicle speed and having a switch normally in position to control a circuit for the purpose of rendering the ignition inoperative but movable upon energization of the control relay to a position for permitting operation of the ignition, said control relay having a second switch closed upon energization of said conthe ignition when its magnet coil is energized, a

second control relay having its magnet coil energized in response to the closing of the ignition switch having a switch closed in response to the energization of its magnet coil for the purpose of connecting the current source with the second measured-time relay magnet coil, said second control relay having a second switch in series with the second measured-time relay switch and being normally in position to control a circuit to render the ignition inoperative but movable into a position for the purpose of permitting operation of the ignition when the second control relay magnet'coil is energized, means under the control of the driver for rendering the second control relay operative, and means responsive to the attainment of a speed below the speed range throughout which the first mentioned control relay is operative for rendering the second control and measured-time relays ineflective to render the ignition inoperative.

6. An ignition control system for automotive 'use comprising a current source electrical ignition apparatus, two time-lag relays operative to withhold ignition for a predetermined time, two control relays respectively operative to precondition the time-lag relays for operation, switches under driver control for respectively rendering the control relays inoperative to maintain the energization of the time-lag relays whereby, during the flux decay periods thereof, operation of ignition is withheld, a vehicle speed responsive switch operative throughout a certain speed range to render one of the control relays eflective to precondition its associated time-lag relay, and a second vehicle speed responsive switch normally controlling a circuit to maintain the effectiveness of the other control relay and its associated time-lag relay to control the ignition only throughout a speed range below that speed range of the first mentioned vehicle-speed responsive switch throughout which the relays associated therewith are effective to control the ignition.

EDWARD M. CLAYTOR. 

